Multi-channel bichromatic product sorter

Claim 1

A sorting apparatus for sorting agricultural products into acceptable and unacceptable categories based on a pattern check and a ratio check of color characteristics of the products as they descend in a chute or conduit through a zone of illumination in a viewing station, comprising: (a) means for sensing the light reflected from successive portion of the product in the zone of illumination at plural sensors about the periphery of the zone of illumination; (b) means for dividing the sensed light reflected from the portions of the product into plural color illumination level components; (c) means for converting the color illumination level components into electrical component level signals; (d) classification means for analyzing the electrical component level signals to determine if the color of individual ones of the product is acceptable, comprising: (1) ratio check circuit means for comparing the ratio of the electrical component level signals to detect unacceptable product; (2) pattern check circuit means for comparing each of the electrical component level signals against a reference level to detect unacceptable product; (3) means for selectively energizing said ratio check circuit means and said pattern check circuit means; (4) product reject means for forming a signal indicating an unacceptable product as detected by at least one of said ratio check circuit means and said pattern check circuit means; (e) control circuit means for selectively enabling said ratio check circuit means and said pattern check circuit means; (f) background means for providing a background illumination level in the zone of illumination when energized; (g) means for enabling said background means when said pattern check circuit means is enabled; (h) means for disabling said background means when said ratio check circuit means is enabled; and (i) ejector means responsive to said product reject means for removing unacceptable product from the descending products.